1. Field of the Invention
The present invention relates to a golf club head and a golf club having a head body made with metal, and to a golf club head to which a crown part is fixed so as to close crown openings and a golf club having such a head.
2. Description of the Background Art
Recently, golf club heads are increasingly manufactured with larger volume, which results in higher center of gravity. A golf club head with such higher center of gravity may hardly raise a ball high when hitting it and may decrease the distance of the ball flight. Accordingly, various attempts have been made to set the center of gravity of a golf club head lower such that it easily raises the ball high and increases the distance of the ball flight.
For example, Japanese Patent Laying-Open No. 8-196665 describes a golf club head, in which a hosel portion is integrally formed, and a through hole penetrating through a vertical direction including the center of gravity of the head to form a ring-shaped head body. A closure plate made with a material smaller in the specific gravity and softer than the head body is secured or fixed to the head body, such that at least one of upper and lower openings of the through hole of the head body is closed.
Japanese Utility Model Publication No. 7-4050 describes a golf club head, in which, in order to provide a large and strong golf club head, a mass body is formed that serves as a framework of the club head by: an integral body of a face portion and a neck portion; a plurality of ribs provided from the back surface of the face portion to the rear end of the club head; and a fixing member for fixing the plurality of ribs at the rear end of the club head. Further, the space in the mass body is filled with a foam body to be a shape of a club head.
Japanese Utility Model Laying-Open No. 6-86757 describes a golf club head, wherein, in order to reduce the weight of the head, increase the strength of the face portion, increase the distance of the ball flight, and provide the player with a soft feeling on impact and easier control of the direction of the ball flight, a depression in the face portion in the head body is provided with a window-like opening having a shape and size accounting for weight distribution and the position of the center of gravity of the entire head at a predetermined position. Additionally, a face plate attached to the depression is formed with a composite material made with a plurality of layers of different strength and stiffness.
With the golf club head according to Japanese Patent Laying-Open No. 8-196665, as it is simply provided with the through hall penetrating through the head body in a vertical direction, the strength of the crown portion of the head body may disadvantageously be decreased even though the closure plate is fixed to the head body.
While Japanese Utility Model Publication No. 7-4050 describes provision of a plurality of ribs from the back surface of the face portion to the rear end of the club head, the ribs cannot reinforce the crown portion. Additionally, it does not disclose or suggest to apply the idea disclosed by the publication to the crown portion. As the ribs reach the back surface of the face portion, the face portion hardly deflects and the distance of the ball flight may disadvantageously be decreased.
With the golf club head according to Japanese Utility Model Laying-Open No. 6-86757, while the strength of the face portion may be improved, reinforcement of the crown portion cannot be achieved. Additionally, it does not disclose or suggest to apply the idea disclosed by the publication to the crown portion.